Wireless Communication Systems for Underground Pipe Inspection

Technology

The inventors have developed a system to enable bidirectional wireless communications between underground in-pipe sensor nodes and an aboveground remote control center. Sensor nodes inside the pipeline are mobile and carried by robots. The wireless communication system includes mobile sensor nodes inside the underground pipeline, aboveground relay nodes deployed along the pipeline, a remote monitoring center, and some mobile communication network from a third-party provider. Sensed information can be transmitted from the sensor nodes to the remote control center, and control commands can be delivered from the control center to the robots and sensor nodes.  The robotic device used for leak detection is built on wheels that propel it along the pipe. It consists of a drum-like membrane that forms a seal across the width of the pipe. When the robot encounters a leak, the flowing liquid distorts the membrane and pulls it slightly toward the leak. This distortion is detected by a piezoelectric system consisting of force-resistive sensors, which wirelessly communicate information back to the aboveground relay nodes and remote control center to signal a leak. 

Problem Addressed

Pipeline leakages are not only wasteful and costly but also potentially dangerous, as leaking gas pipes can explode or leech toxins into the environment. Pipes are most commonly inspected for leaks from within (i.e. “in-pipe”). Ensuring accurate, real-time leak detection requires reliable communication both ways between a remote monitoring center and the in-pipe sensor codes.Developing a communication system for in-pipe inspection has proved challenging. Wired systems are subject to wire damage and limited sensor mobility. Wireless communication requires signals to travel through multiple media, including water, plastic, soil and air, to reach aboveground. Moreover, the in-pipe sensor nodes have a limited battery-based energy supply.  

Advantages

• Energy-efficient communications and prolonged network lifetime
• Robotic system can rapidly and accurately detect leaks of just 1-2 mm in size
• Highly affordable compared to existing systems of leak detectionImproved speed and sensitivity over existing systems  

Publications

Relay Node Placement in Wireless Sensor Networks for Pipeline Inspection. In Proceedings of the American Control Conference, June 17, 2013, 4765-4770. https://doi-org.ezproxy.canberra.edu.au/10.1109/ACC.2013.6580518.

Channel-Aware Relay Node Placement in Wireless Sensor Networks for Pipeline Inspection. IEEE Transactions on Wireless Communications 13, no. 7 (July 2014): 3510-3523. https://doi-org.ezproxy.canberra.edu.au/10.1109/TWC.2014.2323782.

A New Way to Detect Leaks in Pipes. MIT News, June 19, 2014.